1. Field of the Invention
The present invention relates to an imaging device and an imaging method.
2. Description of the Related Art
Some imaging devices, such as digital still cameras and video cameras etc., have an auto exposure (AE) function in which exposure is controlled based on the amount of light received. With this function, the imaging device can adjust the brightness of the photographic subject. In this case, the brightness of the photographic subject changes depending on whether the brightness is adjusted while taking the whole photographic subject as a point of reference or adjusted while taking part of the photographic subject as the point of reference (such as a face of a human subject, for example). For example, when the brightness is adjusted while taking the whole photographic subject as the point of reference, if there is a high luminance light source, such as lighting or a window, around a human subject, the human subject becomes dark, and it is difficult for a photographer to adjust to an expected appropriate brightness.
Here, in order to control exposure when photographing a human subject, it is conceivable to use, for example, face recognition technology. However, known face recognition technology is based on edge information of an image, resulting in a high computational load. Thus, circuit size tends to increase.
On the other hand, technology exists in which attention is focused on the color of the photographic subject, and exposure is controlled by targeting a photographic subject that has a specific color. Technology is disclosed, for example, in Japanese Patent Application Publication No. JP-A-2004-192129, in which a light source is determined and skin color conditions are set, and then regions are detected from the image that have a hue of the skin color. Then, based on the detected regions, brightness correction and white balance correction etc. are performed such that the face of the human subject is reproduced with the appropriate brightness and color. In addition, technology is disclosed, for example, in Japanese Patent Application Publication No. JP-A-2000-69490, in which color components in an optical image are detected and an appropriate exposure value is calculated from the detected color components.